The Physiology Core will provide integrated services to the researchers of the individual projects. The core personnel will work to coordinate physiological testing of animals with each individual project director. The auditory brainstem response will be the primary method to evaluate auditory sensitivity but the breadth of the physiology facilities will be available for more in-depth measures of auditory function such as otoacoustic emissions, cochlear microphonics, compound action potentials or endolymphatic potential. The Physiology Core will also coordinate noise exposures of animals with respect to each investigator?s needs for exposures that will produce either temporary (TTS) or permanent (PTS) threshold shifts to meet the needs of the projects. The Physiology Core will provide all of the standard materials and services to accomplish the physiological measurements. The results obtained from the procedures described in this core will be analyzed for statistical significance with the assistance of the Statistics Department at the University of Michigan. The Core will analyze and prepare graphs for presentation at scientific forums and publication in scientific journals. To further promote efficient and successful Core operation, frequent meetings will discuss progress in research, emerging techniques and assistance future directions. Furthermore, the Core will offer resources for laboratories that would like to replace their current animal models (such as the guinea pig) with mice, which offer distinct advantages by virtue of increasing availability of molecular and genetic information. Procedures are in place for scheduling and prioritization of services and quality control. The Histology Core and Physiology Core will work closely together to coordinate physiological and morphological characterization of animals under experimental conditions.